Remove the POD errors. You can check for POD errors automatically by including Test::Pod to your test suite.

Error: Tk-SMListbox-2.1/lib/Tk/SMListbox.pm -- Around line 278: Expected text after =item, not a bulletAround line 293: Expected text after =item, not a bulletAround line 299: Expected text after =item, not a bulletAround line 308: Expected text after =item, not a bulletAround line 314: Expected text after =item, not a bulletAround line 320: Expected text after =item, not a bulletAround line 407: Expected text after =item, not a bulletAround line 414: Expected text after =item, not a bulletAround line 497: =over without closing =back

If you are using Build.PL define the {requires}{perl} = VERSION field. If you are using MakeMaker (Makefile.PL) you should upgrade ExtUtils::MakeMaker to 6.48 and use MIN_PERL_VERSION parameter. Perl::MinimumVersion can help you determine which version of Perl your module needs.